Halo by Greg Bear Silentium (Forerunner Saga)

In the last years of the Forerunner empire, chaos rules. The Flood--a horrifying shape-changing parasite--has arrived in force, aided by unexpected allies. Internal strife within the ecumene has desperately weakened Forerunner defenses.

Too little, too late, the legal rate of Juridicals is only now investigating possible crimes by the Master Builder and others. Evidence-gathering agents known collectively as Catalog have been dispatched to collect testimony from the Librarian and both Didacts: the Ur-Didact, treacherously abandoned in a Flood-infested system, and the Bornstellar Didact, who accompanies the Librarian as she preserves specimens against the dire possibility of Halo extermination.

Facing the imminent collapse of their civilization, the Librarian and the Ur-Didact reveal what they know about the relationship between the long-vanished Precursors and the Flood.

The Precursors created many technological species, including humanity and the Forerunners. But the roots of the Flood may be found in an act of enormous barbarity, carried out beyond our galaxy ten million years before...

Because of that barbarism, a greater evil looms. Only the Ur-Didact and the Librarian--husband and wife pushed into desperate conflict--hold the keys to a solution. Facing the consequences of a mythic tragedy, one of them must now commit the greatest atrocity of all time-to prevent an insane evil from dominating the entire universe ... in Greg Bear's Halo: Silentium.

Greg Bear, author of over 25 books, which have been translated into 17 languages, has won science fiction's highest honors and is considered the natural heir to Arthur C. Clarke. The recipient of two Hugos and four Nebulas for his fiction, he has been called "the best working writer of hard science fiction" by THE SCIENCE FICTION ENCYCLOPEDIA. Many of his novels, such as DARWIN'S RADIO, are considered to be this generations' classics. He is married to Astrid Anderson, daughter of science fiction great Poul Anderson, and they are the parents of two children, Erik and Alexandria. His recent thriller novel, QUANTICO, was published in 2007 and the sequel, MARIPOSA, followed in 2009. He has since published a new, epic SF novel, CITY AT THE END OF TIME and a generation starship novel, HULL ZERO THREE..